Field of the Invention
The present invention relates to an image pickup apparatus configured to reconstruct a refocused image and a method of controlling the image pickup apparatus.
Description of the Related Art
In image pickup apparatus such as a digital camera, two kinds of methods are known as methods of bringing an object into focus by a user. The first method is a method of adjusting focus by driving a focus lens, called “contrast AF” or “phase detection AF”. The second method is a method called “refocusing”. The “refocusing” is a technology of generating a refocused image in which an object is in focus in the following manner. Specifically, image signals respectively for pupil-division regions, which are read from an image pickup element, are reconstructed as if an image pickup plane were virtually moved in a fore-and-aft direction. The image signals respectively for the pupil-division regions are added to generate the refocused image in which the object is in focus. By using the refocusing technology, an image photographed so that one object is in focus can be refocused so that another object is brought into focus through image processing after recording.
The following image pickup apparatus is proposed in Japanese Patent Application Laid-Open No. 2014-003404 as a related-art image pickup apparatus using the refocusing technology. Specifically, the related-art image pickup apparatus generates a parameter used to reconstruct the refocused image as metadata of image data based on photographing information of an optical system at the time of photographing. Further, in Japanese Patent Application Laid-Open No. 2014-197824, there is proposed an image processing apparatus configured to inform a user of which object is located within a refocusable depth distance range when the refocused image is to be reconstructed.
However, the related art has the following problem.
When the photographed image is refocused by using the refocusing technology, there is a possibility that the image cannot be refocused depending on a view angle position of the object. This is because a refocusable photographing view angle range (hereinafter referred to simply as “refocusable view angle range”) is narrowed when the image pickup plane is virtually moved in the fore-and-aft direction for refocusing the image.
According to the technologies described in Japanese Patent Application Laid-Open No. 2014-003404 and Japanese Patent Application Laid-Open No. 2014-197824, the refocused image is reconstructed based on the refocusable distance range in a depth direction of a photographed image. However, the above-mentioned technologies have a problem in that it is difficult to quickly determine whether or not refocusing for bringing a plurality of objects on the photographed image into focus is possible.